Field of the Invention
Embodiments relate to a touch sensor.
Discussion of the Related Art
In a general method of driving a capacitive touch sensor, driving signals are sequentially sent to driving lines and are subjected to time division processing. This method is a time-division single-line driving method and is easily implemented because demodulation is not required. However, since there is a restriction on the response time, it is difficult to obtain a large number of samples for a 1-line driving signal. In addition, in low-frequency noise environments and large-panel applications, it is difficult to ensure an adequate accumulation processing time for noise filtering.
Methods of driving a touch sensor also include a multi-line driving method, which is a parallel method of simultaneously sending driving signals to a plurality of driving lines. The multi-line driving method refers to a method that can use a signal polarity at the same timing instead of time division processing. The multi-line driving method can ensure a large number of samples as compared to time division processing, and has excellent noise filtering performance. In contrast, the multi-line driving method requires a demodulation circuit for gathering data from the driving lines and may increase complexity and area. In addition, in some multi-line driving methods, since a regular pattern using two different polarities is used, there may be restrictions on creation of large types of patterns within a predetermined response time.